Let me apologize right up front if I sound stupid here, this is my first adventure into programming and I'm trying to learn.

What I'm trying to do is use an ultrasonic rangefinder attached to a servo to scan the area in front of the robot in a 180 degree arc, and record the distances at each degree in an array. Then I want to have my bot scan the area over and over, re-looking that 180 degree arc. When one of the distances changes, that should trigger the bot to fire a laser at the spot where the "intruder" is.